The short answer
Most noise complaints on Bosch WAN machines come down to three checks that need no tools: the feet, the filter and the load. Working them first is not a shortcut - it is how the expensive causes get properly earned.
Symptoms on this family
- A squeal on the first rotation of every wash — Usually the door seal or a belt taking up its slack rather than anything structural.
- The machine walks across the floor on spin — Feet, floor or load. The noise is a symptom of the movement, and stopping the movement stops the noise.
- A metallic rattle at low drum speed — Something loose is riding in the drum or has passed the seal into the sump. It is audible at slow speeds because nothing is masking it.
- Loud only on one programme — Different programmes use different spin speeds, so this normally means the noise has a speed threshold rather than a cause of its own.
- A humming machine that does not turn at all — The motor is being asked to move a drum that will not move, and that is a jammed-drum fault rather than a noise fault.
Causes, most likely first on this family
- Unbalanced or under-loaded drum — First on this family by frequency: a small heavy item alone in a large drum cannot be balanced, so the machine either bangs or refuses to reach speed.
- Transit bolts still fitted or partly backed off — Only on a machine that has been moved, but on such a machine it is the very first thing to check and the noise is unmistakable.
- Foreign object in the sump or between drum and tub — Coins, wires and clips pass the seal and grind continuously. It ranks high here because it is common and because it does real damage if left.
- Drain pump impeller fouled — Produces a harsh noise on drain only, which is why the timing of the noise within the cycle matters so much on this diagnosis.
The diagnostic order for these models
- Press and release each cabinet panel while the noise runs — A rattle that changes under your hand is panel resonance and needs no part at all.
- Run a spin with the drum empty — It removes the load variable entirely, which is the single biggest source of noise on this family, and it costs one short cycle.
- Listen for whether the noise tracks drum speed — Speed-tracking noise is mechanical and in the rotating assembly; constant noise is not, and that split is the most useful one you can make.
- Rock the cabinet at each corner — Any movement means a foot is not carrying weight, and everything downstream of that is unreliable until it is fixed.
What to do before you start
Safety
Unplug the washer or switch off its breaker before removing any panel. A capacitor can hold a charge after the power is off, and on a drum machine the motor control board is the last thing to let go of it.
Models in the WAN family
Reference| Model number | Family key |
|---|---|
| WAN24123AU | bosch:washer:wan |
| WAN24124AU | bosch:washer:wan |
| WAN24125AU | bosch:washer:wan |
| WAN28227AU | bosch:washer:wan |
| WAN28288AU | bosch:washer:wan |
When to stop and book a visit
The line here is the drum. The filter, the hoses, the taps and the load are yours; anything that needs the drum out, the tub split or a board read belongs to a technician with the bench space to do it.
Other pages for this family
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Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
